Delaying pregnancy must be a main goal. Health education solves.

Info Reports September 04 (“Obstetric Fistula Ending the Silence, Easing the Suffering”, http://www.infoforhealth.org/inforeports/fistula/fistulaprint.html)
Reducing the number of adolescent pregnancies is one of the first steps to decreasing the frequency of pregnancy complications, including obstetric fistulas. As mentioned, most fistulas occur to adolescent girls, whose bodies may not be fully developed for childbearing (58).
Postponing age at first marriage, delaying age at first pregnancy, and spacing births further apart would help reduce complications of childbirth. Changes in traditions that encourage early marriage and childbearing would allow more young women to reach full physical maturity before beginning childbearing (71).
Helping women plan pregnancies is important to reducing the incidence of fistula. Many women living in rural areas, where fistula is most common, have little access to family planning information and services (63).
Strengthening the capacity of health care systems could improve family planning services to the rural poor. Better access to a range of contraceptive methods would help more people choose and continue using a method of their choice.
Offering more schooling and family life education for women also can help reduce obstetric fistulas (71). In particular, expanding health education and family planning programs will provide more women with information and services to delay childbearing until they are ready. Schooling helps young women raise their economic and social status and promotes maternal health (21).